It is cheaper to buy a two-bedroom home than rent one in 72% of major metropolitan areas around the U.S., according to the Trulia rent vs. buy index released Monday.

The real estate data firm said increased demand for rental properties is driving the cost of homeownership down nationwide.

“Since the start of the Great Recession, many former homeowners have flooded the rental market,” said Pete Flint, chief executive and co-founder of Trulia. “Following the principles of supply and demand, renting has become relatively more expensive than buying in most markets.”

Trulia compared the median list price of a two-bedroom home with the median price paid for rent in 50 cities. The company then assigned a price-to-rent ratio to each city, with any number below 15 signifying a homebuyer’s market and any number above 21 signifying a renter’s market. Any market between those two numbers has more balanced rent versus buy costs.